Skin problems including diaper dermatitis are believed to be caused by the prolonged contact of the skin with skin active environmental factors including ammonia, UV-light, moisture, bacteria, urine, non-neutral pH, and others. Because these various suspected factors have different properties and require different approaches, the most effective method of treating skin has been the application of a topical protective barrier agent between the skin and the skin active environmental factors.
A detailed disclosure of topically applied barrier agents is disclosed in EP-A-328 355 which relates in general to wet wipes comprising low viscosity emulsion systems.
Baby wet wipes are premoistened, disposable towelettes used primarily during diaper changes for cleansing. The wipe is typically constructed of combinations of synthetic (e.g. polyolefin) fibers, viscose fibers, cotton fibers, and cellulose fibers. It is possible to also produce wipes from other synthetic or natural fibers not mentioned. Wipes are generally moistened with water and contain various combinations of emulsion systems, cleaning, surfactants, preservatives and scents. A detailed disclosure of baby wet wipes and ingredients they contain is also contained in EP-A-328 355.
In order to provide cleaning and skin treatment the combination of wipes and a protective barrier agent is typically used. The wipes are used initially, for cleansing, and than a barrier agent is applied for skin protection. Baby wipes currently available do not leave substantive or wash resistant residues to protect the skin, so called barrier agents, after application. Barrier agents are generally greasy and unappealing and are not effective cleansing agents. In addition, the used of some barrier agents may actually promote excessive skin hydration which may result in increased skin fraction.
There is thus a need in the treatment of skin for a hybrid product which would effectively cleanse and also leave a substantive protection residue on the skin. It would also be desirable to be able to apply the hybrid product premoistened as a wipe. The protective residue further should not significantly reduce transepidermal moisture loss.
EP-A-85 334 describes an oil in water composition comprising 40-95% water and 0.01-5% of an emulsifier. It is concerned with the formation of dermatologically acceptance of substantive topical oil in water emulsions which are useful for sunscreen composition applications. The document discloses composition incorporating a polyanhydride resin derived from a octadence-1 and maleic anhydride. The document is not concerned with forming a stable emulsion according to the present invention.
EP-A-268 164 is concerned with emulsions which contain a modified copolymer of a preponderant amount of an acrylic acid and a smaller amount of a long chain acrylate monomer. The emulsifier are stated to be stable over a period of over one year at room temperature but exhibit quick breaking properties when in contact with an electrolyte or the skin, instantaneously coalescing and releasing the oil. The use of highly cross linked polyacrylic acids in the formation of the emulsion is disclosed but not desirable in the context of wet-wipe applications which comprise electrolytes such as surfactants and preservatives/stabilisers.
EP-A-328 355 is concerned with oil-in-water emulsions which contain silicones and amphipathic emulsifying agents. Concentrate emulsions are formed using high shear forces, and then diluted with water to obtain the final emulsion. The emulsions are said to have viscosities of less than 100 mpas.
The present invention relates to wet-wipes with silicone-phase-in-water emulsions providing a medium to low viscosity for good cleaning, a polymeric emulsion system to reduce surfactant residue on the skin and a micorbial stabiliser providing storage stability. The present invention provides hence an alternative/a selection to the emulsions disclosed in EP-A-328 355.